Incandescent electric lamp.



No. 653,038. Patented July 3, I900.

J. PLECHATI. INCANDESOENT ELECTRIC LAMP.

(Application filed Nov. 13, 1899.)

' (No Model.)

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UNITED STAT-Es mENT Enron.

JOSEF PLEGI-IATI, OF BERLIN, GERMANY.

INCANDESCENT ELECTRIC LAMP.

SPEGIFICA TION forming part of Letters Patent No. 653,038, dated July 3,1900. Application filed November 13,1899. Serial No. 736,757. (Nomodel.)

To all whom it may concern.-

Be it known that I, J OSEF PLECHATI, a citizen of the Empire of Germany,residing in Berlin, in the Kingdom of Prussia, Germany, have inventedcertain new and useful Improvements in Incandescent Electric Lamps, ofwhich the following is a specification.

This invention relates to improvements in incandescent electric lamps,and more particularly to improvements in that class of lamps in whichthe bulb is made easily detachable from its socket, so that it maybewithout difficulty removed therefrom whenever it is desired to repaireither the bulb or socket or to exchange the bulb for one of anothercolor, as may sometimes be desired for decorative purposes.

The object of the invention is to provide for such lamps a secure andreliable and at the same time simple means for connecting the bulb tothe socket; and the invention consists in the combination, in anincandescent electric lamp, of a socket, a'lamp-bulb having a contractedportion or neck, points or teats projecting from said neck, and ahelical spring interposed between and in frictional contact with thesocketand lamp-bulb, said points or teats entering between the convolutions of said spring and preventing the turning of the lamp-bulbrelatively thereto.

The invention consists, further, in the interposition of afriction-layer or roughened layer of any suitable material between thehelical spring and the lamp-bulb, so that the metallic spring does notcome into direct contact with the bulb.

In the accompanying drawings, Figure l is a side view of an incandescentlamp-bulb constructed according to my invention. Fig. 2 is a verticalcentral section through the bulb and socket; and Fig. 3 is a horizontalsection on line 00 00, Fig. 2.

Similar letters of reference indicate corresponding parts.

In the drawings, a indicates the bulb of my improved incandescentelectric lamp. The bulb is preferably made of glass and is provided atits lower portion with acontraction or neck I), from which project smallpoints or teats c, which are preferably made integral with the bulb. Aband d, of any suitable frictional material, is placed around the bulbat the contracted portion or neck I) and provided .with perforationsthrough which project the teats c, as shown in Fig. 1. The socket of thelamp consists of a sheetmetal casing or shell h,which is provided withan exterior screw-thread in the usual manner and with a body of cementor other suitable insulating material at the bottom of the shell and ametallic tip 70 at the extreme base of the socket. At its upper portionthe sheetmetal shell is provided with'an annular shoulder or flange andan upright rim surrounding said shoulder. In the seat thus formed islocated a helical spring c. When the glass lamp-bulb is inserted in thesocket,the spring, which has been previously inserted in the socket,enters the contracted portion of the bulb and is pressed into frictionalcontact at the one side with the socket-wall and at the other side intofrictional contact with the friction-layer d, as clearly shown in Fig.2. At the same time the teats or points 0 enter between the convolutionsof the helical spring, as shown in Figs. 2 and 3. By so doing theyprevent the turning of the bulb relatively to the spring and socket,while the friction of the spring with the socket-rim and its engagementwith the neck of the bulb prevent the withdrawal of the bulb from thesocket under ordinary use, although the friction is not so strong as toprevent forcible withdrawal when desired. The layer at, of roughenedmaterial, prevents the direct contact of the metallic spring with theheated bulb, and thereby aids in keeping down the temperature of thespring, so that it retains its temper and strength. For this purpose thelayer (1 is preferably made of some material Which is a non-conductor ora poor conductor of heat. By its friction it serves to prevent theaccidental withdrawal of the bulb from the socket.

The conducting-wires for the incandescent lamp are connected to thefilament of the lamp-bulb and at their opposite ends, respectively, tothe metallic shell h of the socket and tip 70 of the same. It is obviousthat the socket-wall k may be of any suitable shape at its upper portionand not confined strictly to the form shown, although by reason of itsupright rim the latter possesses the advantage of permitting theinsertion of a bulb,

which has the spring already sprung upon it, as well as the removal ofthe bulb with the spring remaining contracted around the same.

Having thus described my invention, I claim as new and desire to secureby Letters Patent-- 1. In an incandescent electric lamp, a socket, alamp-bulb having a contracted portion or neck, points or teatsprojecting from said neck, and a helical spring interposed between andin frictional contact with the socket and lamp-bulb, said points orteats entering between the convolutions of said spring and preventingthe turning of the lamp relatively thereto, substantially as set forth.

2. In an incandescent electric lamp, a socket, a lamp-bulb having acontracted portion or neck, a layer of heat-insulating material appliedto the contracted portion or neck of the bulb, and a helical springinterposed between and in frictional contact with the socket and saidheat-insulating layer, substantially as set forth.

3. In an incandescent electric lamp, a

socket, a lamp-bulb having a contracted portion or neck, afriction-layer applied to the contracted portion or neck of the bulb,and a helical spring interposed between and in frictional contact withthe socket and said friction-layer, substantially as set forth.

4. In an incandescent electric lamp, a socket, a lamp-bulb having acontracted portion or neck, points or teats projecting from said neck, aperforated friction-layer applied to the contracted neck or bulb, and ahelical spring interposed between and in frictional contact with thesocket and said frictionlayer, said points or teats passing through theperforations of said friction-layer and entering between theconvolutions of said spring, substantially as set forth.

In testimony that I claim the foregoing as myinvention I have signed myname in presence of two subscribing Witnesses.

J OSEF PLEOHATI.

\Vitnesses:

HENRY HASPER, WOLDEMAR HAUPT.

